Spring Boot

Spring Boot example –

• Go to Spring Initializer
• Select Project as Maven Project
• Select Language as Java
• Select Spring Boot with the latest version (not the SNAPSHOT version)
• Enter details in Project Metadata
  • Group – Enter package name
  • Artifact – Enter the project name
  • Name – Enter the project name
• Add dependencies
  • Web
  • DevTools
• Generate project
• Extract the zip file and import the project in IDE

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.4.2</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.misstechack</groupId>
	<artifactId>spring-boot-demo</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>spring-boot-demo</name>
	<description>Demo project for Spring Boot</description>
	<properties>
		<java.version>1.8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-devtools</artifactId>
			<scope>runtime</scope>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

Student.java

package com.misstechack.demo;

public class Student {
	private String rollNo;
	private String name;
	
	public String getRollNo() {
		return rollNo;
	}
	public void setRollNo(String rollNo) {
		this.rollNo = rollNo;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
}

Controller Class – StudentController.java

package com.misstechack.demo;

import java.util.HashMap;
import java.util.Map;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.DeleteMapping;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.PutMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class StudentController {
	private static Map<String, Student> repo = new HashMap<>();
	static {
		Student student1 = new Student();
		student1.setRollNo("1");
		student1.setName("Amar");
		repo.put(student1.getRollNo(), student1);
		
		Student student2 = new Student();
		student2.setRollNo("2");
		student2.setName("Dolly");
		repo.put(student2.getRollNo(), student2);
	}
	
	@GetMapping("/Students")
	public ResponseEntity<Object> getStudent() {
		return new ResponseEntity<>(repo.values(), HttpStatus.OK);
	}
	
	@PostMapping("/Students")
	public ResponseEntity<Object> createStudent(@RequestBody Student Student) {
		repo.put(Student.getRollNo(), Student);
		return new ResponseEntity<>("Student is created successfully", HttpStatus.CREATED);
	}
	
	@PutMapping("/Students/{id}")
	public ResponseEntity<Object> updateStudent(@PathVariable("id") String id, @RequestBody Student Student) {
	repo.remove(id);
	Student.setRollNo(id);
	repo.put(id, Student);
		return new ResponseEntity<>("Student is updated successfully", HttpStatus.OK);
	}
	
	@DeleteMapping(value="/Students/{id}")
	public ResponseEntity<Object> deleteStudent(@PathVariable("id") String id) {
		repo.remove(id);
		return new ResponseEntity<>("Student is deleted successfully", HttpStatus.OK);
	}
	
}	

Application Class

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class Application {

	public static void main(String[] args) {
		SpringApplication.run(Application.class, args);
	}

}